The State of Kerala falls in the humid tropical belt with high rainfall and temperature conditions conducive to
intense weathering processes. Kerala has dominantly highly weathered lateritic soils which are acidic, kaolinitic, gravelly with low cation
exchange capacity, low water holding capacity and high phosphorus fixation. Soils are inherently poor in bases and other plant nutrients.
However, they are responsive to agronomic management. The continuous downward slide in crop production has been a matter of serious concern.
Improving and maintaining soil fertility for productivity enhancement is of paramount importance in sustaining crop production.
The Kerala State Planning Board initiated a project on “Soil Based Plant Nutrient Management Plan for Agro-Ecosystems of Kerala” in 2010. The project implemented by the Department of Agriculture was organized as a multi-institutional Project of the State and Central institutions involved in agricultural research and development in the State under the leadership of NBSS & LUP, Bengaluru and co-ordinated by the Kerala State Planning Board.
Around 2 lakhs of surface soil samples were collected from individual farmer’s fields covering all the local bodies
in the State. Collection of samples was coordinated by the Nehru Yuva Kendras (Govt. of India) and the National Bureau of Soil Survey and
Land Use Planning (ICAR), Benguluru. The samples were analysed for major, secondary and micro nutrients (13 parameters) utilising the
facilities and expertise of 27 laboratories under the various collaborating institutions. The analytical data were uploaded to the central
server located in the Agri informatics division of the Indian Institute of Information Technology and Management- Kerala (IIITM -K) .
Appropriate offline and online software have been developed by IIITM - K with the support of Kerala Agricultural University and NBSS & LUP,
Bengaluru and other collaborating institutions in the project for data entry by the participating laboratories and for data interpretation and
analysis, facilitating soil test based fertiliser recommendation for various crops for macro, secondary and micro nutrients.
Nutrient Advisory cards have been issued to the individual farmers covered under the project. The cards can also be accessed by individual
farmers using the soil sample code by visiting www.keralasoilfertility.net. Agriculture Departmental officials and concerned scientists of
the collaborating institutions can also access the soil health cards by logging on to the website.
The flow chart of the project (given below) shows the sequence of events and activities from soil sample collection to issue of soil health cards, preparation of nutrient management plans etc.
PROJECT ON SOIL BASED PLANT NUTRIENT MANAGEMENT PLAN FOR
AGRO ECO-SYSTEMS OF KERALA
SUMMARY OF ACTIVITIES OUTPUT
- 1. Kerala State Planning Board
- 2. National Bureau of Soil Survey and Land Use Planning (ICAR), Benguluru
- 3. Kerala Agricultural University, Thrissur
- 4. Department of Agriculture (Govt. of Kerala)
- 5. Kerala Forest Research Institute (GOK)
- 6. Central Tuber Crop Research Institutef(ICAR)
- 7. Central Plantation Crop Research Institutef(ICAR)
- 8. Krishi Vigyan Kendras
- 9. Indian Cardamom Research Institute,(GOI)
- 10. Indian Institute of Spices Research, (ICAR)
- 11. Indian Institute of Information Technology and Management (GOK)
- 12. National Centre of Earth Science Studies (GOI)
SPECIAL FEATURES OF THE PROJECT
- The multi-institutional collaboration brought together planners, research scientists, officers of the department of Agriculture to address a serious concern of the State
- Testing of soils for secondary and micro-nutrients apart from macro nutrients
- Extensive use of Information Communication Technology (ICT) for soil test data transmission, storage, analysis and automated processing to generate soil test advisories to farmers
- Re-organisation of the soil testing services in the State: revision of the soil testing manual and inclusion of the analysis soils for the secondary nutrients (calcium, magnesium and sulphur) and micro-nutrients (iron, manganese, copper, zinc and boron)
- Initiation of a network research programme to evolve package of practices for secondary and micro nutrients for crops grown in the State
The gravel content in laterite soils of Kerala ranges from 15 to 70 per cent. The gravelliness factor depending
on the soil texture increases the bulk density which adversely affects the foraging capacity of plant roots for nutrients. The decrease
in soil volume also leads to poor inherent soil fertility, lesser available water capacity and other hydrological properties. The low water
holding capacity of the low activity clays also brings about water stress in the root zone during summer months. This is especially severe in
the northern districts of the state.
SOIL HEALTH CARD
As part of the project, software for online data capturing, processing and generation of soil health cards was developed
by IIITM-K, Thiruvananthapuram. The basic details of farmer with address, land and crop and soil analysis data (pH, EC, major, secondary and
micro nutrients) were captured through an online interface from all the 27 participating laboratories to generate a unique sample code and
farmer ID. Farmer ID is generated through a systematic approach by adopting a combination of alpha numeric characters. It is structured by
integrating a combination of 3 letter character of the district, taluk, panchayat and survey number of the plot, followed by the serial number
of the soil sample collected from the field. For example, in the farmer ID ‘ TVM/NYK/CKL/368/29-2/106587’ the first three letters represents
the district code, followed by the taluk, panchayat, survey number of the plot and serial number of the soil sample.
The captured data were validated through a systematic validation mechanism and the data were passed into the data analysis interpretation process to generate soil health cards for each crop. The soil health cards provide detailed information on soil analysis data, soil fertility ratings and recommendations for lime, organic manure and chemical fertilizers supplying major, secondary and micro nutrients as per the Packages of Practices (2012), Kerala Agricultural University.
The entire processed data have been archived into a centralized environment in district/block/panchayat/crop/laboratory wise for easy retrieval and access. A web portal (www.keralasoilfertility.net) has also been developed for retrieval of data and access of soil test results and fertilizer recommendations (soil health cards) by scientists, agricultural officers and farmers through necessary authentication.
NUTRIENT MANAGEMENT PLAN
Soil analysis data from farmer’s field formed the basis for the preparation of area wise soil test summaries and
fertilizer recommendations. Nutrient indices have been worked out for major nutrients N, P and K. Fertilizer recommendations are based on
the frequency distribution of nutrient in the low, medium and high fertility classes. In respect of secondary and micro nutrients the
frequency of the deficient/adequate classes decides the need for nutrient supplements. Fertilizer recommendation for various crops and
guidelines for fertilizer use have been suggested.
Nutrient management plan assists the farmers in the proper choice and use of organic manures and fertilizers. Since the recommendations are soil test based, there is potential savings in input cost, balanced supply of nutrients based on the need of the crop and improved crop performance. Enhanced crop yield and quality with lesser environmental hazards due to excess of nutrients and improvement in soil health are added benefits. Nutrient management plans were prepared for all the local bodies in the State and provides an overview of the fertility status. The panchayat nutrient management plans were integrated to develop plans for the Blocks and Districts of the state.
SOIL FERTILITY CONSTRAINTS IDENTIFIED AND INTERVENTIONS SUGGESTED UNDER THE PROJECT
Majority of the soils of Kerala are strongly acid to moderately acid, available P status is high in majority of soils,
wide spread deficiency of magnesium and boron and deficiency of zinc in limited areas are the salient findings.
Regular liming practice based on pH, reduction in P application to the extent of 50 per cent of the recommended POP and application of secondary and micronutrient fertilizers based on soil test are suggested.